Smooth hybrid inflation on brane constrained by Planck data

2014 ◽  
Vol 29 (26) ◽  
pp. 1450146 ◽  
Author(s):  
M. Ferricha-Alami ◽  
H. Chakir ◽  
J. Inchaouh ◽  
M. Bennai
Keyword(s):  
Spectral Index ◽  
Index Formula ◽  
Type Ii ◽  
Planck Data ◽  
Inflation Model ◽  
Scalar Spectral Index ◽  
Central Value ◽  
Hybrid Inflation ◽  
Kähler Potential ◽  
Braneworld Model

It is shown that, in the supersymmetric smooth hybrid inflation model with the minimal Kähler potential, the spectral index ns is larger than 0.97 in the standard inflation. In this context, we study the smooth hybrid inflationary model in the framework of the Randall–Sundrum type-II braneworld model. We derive all known inflationary spectrum parameters which are widely consistent with Planck data for a particular choice of brane tension values λ especially for number of e-folds N = 50. We reproduce the central value of the scalar spectral index ns = 0.96 whereas the ratio r~(10-4-10-3). However, the running of the scalar spectral index [Formula: see text] is not excluded from the range given by the latest observational measurements.

New constraint of an attractor GL model in braneworld context

2017 ◽  
Vol 32 (19n20) ◽  
pp. 1750119
Author(s):  
Z. Mounzi ◽  
A. Safsafi ◽  
M. Ferricha-Alami ◽  
M. Bennai
Keyword(s):  
Power Spectrum ◽  
Spectral Index ◽  
Index Formula ◽  
Brane Tension ◽  
Inflation Model ◽  
Scalar Spectral Index ◽  
Central Value ◽  
Braneworld Model ◽  
Inflationary Parameters

We are interested in studying the generalization of the first chaotic inflation model in supergravity, which was proposed by Goncharov and Linde (GL model) and was recently revisited, in the framework of the Randall–Sundrum type 2 braneworld model. This model predicts a tiny ratio [Formula: see text] and [Formula: see text]. Our scenario predicts a great tensor-to-scalar ratio [Formula: see text] of the order [Formula: see text] and the central value of the scalar spectral index [Formula: see text] for a particular choice of values of brane tension [Formula: see text] and the parameter [Formula: see text]. We have shown that this scenario reproduces successfully an attractor behavior. We have also derived all known spectrum inflationary parameters, in particular the running [Formula: see text] and the power spectrum of the curvature perturbations [Formula: see text] which are widely consistent with Planck observations.

PERTURBATIONS FROM D-TERM INFLATION

2007 ◽  
Vol 22 (25n28) ◽  
pp. 2035-2038
Author(s):  
OSAMU SETO ◽  
JUN'ICHI YOKOYAMA
Keyword(s):  
Spectral Index ◽  
Cosmic String ◽  
Cosmic Strings ◽  
Unit Length ◽  
Higher Order ◽  
Inflation Model ◽  
Scalar Spectral Index ◽  
String Problem ◽  
Kähler Potential ◽  
Higher Order Corrections

We investigated a simple D-term inflation with taking account of higher order corrections in the Kähler potential. These terms may solve the cosmic string problem in D-term inflation model. The mass per unit length of cosmic strings formed after inflation can be suppressed enough. In addition, the change of the potential slope leads simultaneously a more tilted scalar spectral index ns ≃ 0.96 – 0.97 than that in the model without these corrections.

scholarly journals On Chaplygin Gas Braneworld Inflation with Monomial Potential

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
A. Safsafi ◽  
I. Khay ◽  
F. Salamate ◽  
H. Chakir ◽  
M. Bennai
Keyword(s):  
High Energy ◽  
Chaplygin Gas ◽  
Type Ii ◽  
Energy Limit ◽  
Generalized Chaplygin Gas ◽  
Planck Data ◽  
Central Value ◽  
Braneworld Model ◽  
Perturbation Parameters ◽  
Braneworld Inflation

We study the Chaplygin gas model as a candidate for inflation in the framework of the Randall-Sundrum type II braneworld model. We consider the original and generalized Chaplygin gas model in the presence of monomial potential. The inflationary spectrum perturbation parameters are reformulated and evaluated in the high-energy limit and we found that they depend on several parameters. We also showed that these perturbation parameters are widely compatible with the recent Planck data for a particular choice of the parameters space of the model. A suitable observational central value of ns≃0.965 is also obtained in the case of original and generalized Chaplygin gas.

scholarly journals Quantum smearing in hybrid inflation with chaotic potentials

2016 ◽  
Vol 25 (03) ◽  
pp. 1650035
Author(s):  
Waqas Ahmed ◽  
Ommair Ishaque ◽  
Mansoor Ur Rehman
Keyword(s):  
Spectral Index ◽  
Radiative Correction ◽  
Active Role ◽  
Index Formula ◽  
Tree Level ◽  
Correction Formula ◽  
Scalar Spectral Index ◽  
Hybrid Inflation ◽  
The Impact ◽  
Reheating Process

We study the impact of 1-loop radiative corrections in a nonsupersymmetric model of hybrid inflation (HI) with chaotic (polynomial-like) potential, [Formula: see text]. These corrections can arise from the possible couplings of inflaton with other fields which can play an active role in the reheating process. The tree-level predictions of these models are shown to lie outside of the Planck’s latest bounds on the scalar spectral index [Formula: see text] and the tensor to scalar ratio [Formula: see text]. However, the radiatively corrected version of these models, [Formula: see text], is fully consistent with the Planck’s data. More specifically, fermionic radiative correction ([Formula: see text]) reduces the tensor to scalar ratio significantly and a red-tilted spectral index [Formula: see text], consistent with Planck’s data, is obtained even for sub-Planckian field-values.

scholarly journals Nonminimal inflation in supersymmetric GUTs with U(1)R × Zn symmetry

2019 ◽  
Vol 28 (16) ◽  
pp. 2040015
Author(s):  
Muhammad Atif Masoud ◽  
Mansoor Ur Rehman ◽  
Mian Muhammad Azeem Abid
Keyword(s):  
Spectral Index ◽  
Index Formula ◽  
Global Symmetry ◽  
Perfect Agreement ◽  
Grand Unified Theories ◽  
Scalar Spectral Index ◽  
Unified Theories ◽  
Hybrid Inflation

A supersymmetric hybrid inflation framework is employed to realize a class of nonminimal inflation models with [Formula: see text] global symmetry. This framework naturally incorporates models based on grand unified theories by avoiding the most commonly faced monopole problem. The predictions of inflationary observables, the scalar spectral index [Formula: see text]–0.966 and the tensor to scalar ratio [Formula: see text]–0.0045, are in perfect agreement with the Planck 2018 data. For sub-Planckian values of the field the [Formula: see text] symmetry is only allowed for [Formula: see text].

scholarly journals α-Attractors and reheating in a nonminimal inflationary model

2020 ◽  
Vol 29 (10) ◽  
pp. 2050077
Author(s):  
R. Shojaee ◽  
K. Nozari ◽  
F. Darabi
Keyword(s):  
Scalar Field ◽  
Spectral Index ◽  
Parameter Space ◽  
Model Potential ◽  
Index Formula ◽  
Inflationary Model ◽  
Scalar Spectral Index ◽  
Canonical Scalar Field

We study [Formula: see text]-attractor models with both E-model and T-model potential in an extended Nonminimal Derivative (NMD) inflation where a canonical scalar field and its derivatives are nonminimally coupled to gravity. We calculate the evolution of perturbations during this regime. Then by adopting inflation potentials of the model we show that in the large [Formula: see text] and small [Formula: see text] limit, the value of the scalar spectral index [Formula: see text] and tensor-to-scalar ratio [Formula: see text] are universal. Next, we study reheating after inflation in this formalism. We obtain some constraints on the model’s parameter space by adopting the results with Planck 2018.

Reconstruction of warm Chaplygin gas inflationary models

2020 ◽  
Vol 35 (32) ◽  
pp. 2050268
Author(s):  
Abdul Jawad ◽  
Shamaila Rani ◽  
Kazuharu Bamba ◽  
Nadeem Azhar
Keyword(s):  
Spectral Index ◽  
Effective Potential ◽  
Chaplygin Gas ◽  
Index Formula ◽  
Curvature Perturbation ◽  
Warm Inflation ◽  
Scalar Spectral Index ◽  
Dissipative Coefficient ◽  
Inflationary Parameters ◽  
Friedmann Robertson Walker

By assuming the specific Chaplygin gas model, we study the reconstruction of warm inflation model with the help of tensor-to-scalar ratio [Formula: see text] and scalar spectral index [Formula: see text]. In this regard, we take flat Friedmann–Robertson–Walker (FRW) metric and discuss the general forms of dissipative coefficient [Formula: see text] as well as effective potential [Formula: see text] for two dissipative regimes i.e., the weak and strong. We use inflationary parameters such as slow-roll parameters, power spectrum of the curvature perturbation, tensor spectrum, spectral index, scalar-to-tensor ratio and Hubble parameter to find the generalized form of dissipative coefficient and effective potential. We discuss the results of dissipative coefficient and reconstructed potential in detail for the specific choice of tensor-to-scalar ratio [Formula: see text] and scalar spectral index [Formula: see text].

Shaft potential inspired warm inflation

2017 ◽  
Vol 14 (06) ◽  
pp. 1750088 ◽  
Author(s):  
Abdul Jawad ◽  
Amara Ilyas ◽  
Sarfraz Ahmad
Keyword(s):  
Scalar Field ◽  
Spectral Index ◽  
Power Spectra ◽  
Spectral Indices ◽  
Tensor Power ◽  
Planck Data ◽  
Warm Inflation ◽  
Slow Roll ◽  
Scalar Spectral Index ◽  
Inflationary Parameters

We discuss the warm inflation in the presence of shaft potential [Formula: see text], tachyon scalar field and the generalized form of dissipative coefficient [Formula: see text]. In this respect, we investigate the inflationary parameters (slow-roll parameters, number of e-folds, scalar-tensor power spectra, spectral indices, tensor-to-scalar ratio and running of scalar spectral index) in both strong and weak dissipative regimes. It is interesting to mention that our inflationary parametric results (tensor-scalar ratio, spectral index and running of spectral) are consistent with the recent observational data such as BICEP[Formula: see text], WMAP[Formula: see text] and latest Planck data.

scholarly journals WMAP5 OBSERVATIONAL CONSTRAINTS ON BRANEWORLD NEW INFLATION MODEL

2010 ◽  
Vol 25 (01) ◽  
pp. 171-183 ◽  
Author(s):  
R. ZARROUKI ◽  
Z. SAKHI ◽  
M. BENNAI
Keyword(s):  
High Energy ◽  
Observational Constraints ◽  
Type Ii ◽  
Energy Limit ◽  
High Energy Limit ◽  
Inflation Model ◽  
Slow Roll ◽  
Braneworld Model ◽  
Perturbation Spectrum ◽  
Good Agreement

We study a new inflation potential in the framework of the Randall–Sundrum type II braneworld model. Using the technic developed in Ref. 1, we consider both a monomial and a new inflation potentials and apply the slow-roll approximation in high energy limit, to derive analytical expression of relevant perturbation spectrum. We show that for some values of the parameter n in the potential [Formula: see text] we obtain a perturbation spectrum which gives a good agreement with the recent WMAP5 observations.

scholarly journals F-TERM BRANEWORLD INFLATION IN LIGHT OF FIVE-YEAR WMAP OBSERVATIONS

2010 ◽  
Vol 25 (17) ◽  
pp. 3445-3451 ◽  
Author(s):  
A. BOUAOUDA ◽  
R. ZARROUKI ◽  
H. CHAKIR ◽  
M. BENNAI
Keyword(s):  
Scalar Potential ◽  
Fine Tuning ◽  
Type Ii ◽  
Brane Tension ◽  
Coupling Constant ◽  
Analytical Expression ◽  
Hybrid Inflation ◽  
Braneworld Model ◽  
Braneworld Inflation

We consider a supersymmetric hybrid inflation in the framework of the Randall–Sundrum type II braneworld model. We derive an analytical expression for the scalar potential and find that the F-term dominates the hybrid inflation process. We show that, for some value of brane tension, we can eliminate the fine-tuning problem related to coupling constant κ of the potential. We also calculate all known spectrum inflation parameters and show that observational bounds from WMAP5, BAO and SN observations are satisfied.

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